Fundamentals of Biology: Lecture Outline - Chapter 5
Cell Membranes
FLUID MOSAIC MODEL:
- cell membranes composed mostly of
- phospholipid molecules have
hydrophilic heads +
- Lipid bilayer = hydrophobic barrier
- Proteins embedded in bilayer
What exactly do we mean by "Fluid-Mosaic"?
FLUID?
MOSAIC?
Membrane Proteins:
Adhesion proteins
Communication proteins
Receptor proteins
Recognition proteins
Transporter proteins
Channel
Carrier
Selective Permeability
Diffusion:
Rate + direction of diffusion are affected by:
1.
2.
3.
4.
5.
When gradients no longer exist =___________________ _________________
Crossing Mechanisms:
Transporters
PASSIVE Transport
- flow from high to low
- binding site on membrane
ACTIVE Transport
- "pumps"
- move solutes against concentration gradients
- requires
Osmosis
- diffusion
- of water
- across
Tonicity:
Hypotonic
Hypertonic
Isotonic
Hydrostatic pressure
Osmotic pressure
Exocytosis
Endocytosis - 3 ways
1. Receptor-mediated
2. Bulk phase
3. Phagocytosis
Review
Chapter 5 - page 95
Review questions 1-7
Self quiz 1-8
Critical thinking #1 and 2